It is neither new nor unusual for humans to grow plants for ornament or for food in places and by means that are unnatural. Growing plants in pots, e.g., as house plants, is a widespread example. Growing plants hydroponically is another.
There are more esoteric examples: the Indians, 600 years ago in what now is suburban Mexico City, Mexico, grew crops on floating rafts from which the plant roots dangled into the water.
Without exception in these prior efforts, so far as the present inventor is aware, nutrients for the plants were applied without using a device that will prevent the plant nutrients from contaminating the soil water. As the result sometimes a situation is created where the plants are unable readily to get plain water from the soil when the need of it arises. Plant nutrients are commonly supplied to the plants without water or without soil. It is quite common to find plant nutrients in organic or in inorganic form being directly applied to the soil. Plain water containing insignificant amounts of plant nutrients can be found in many types of soil. A soil can fix a small quantity of applied nutrients, and when nutrients are applied within the limit of the soil's capability to fix them, the plants readily can get plain water supply from the soil. However, when a large quantity of nutrients is used to increase the yield from the soil, a situation can arise where the soil fixing capability cannot cope with the load, the surplus nutrients get into the soil water, and under certain situations, can cause injury to the plant. The present invention solves the difficult problem of soil water contamination encountered when a large quantity of chemical fertilisers is required to be used in order to raise the high productivity of the soil.